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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 86-102页

作者： G.kovács the Ganz Electric Works BudapestHungary

The harmonics that appear in the squirrel cage asynchronous machine have been discussed in great detail in the literature for a long time. However, the systematization of the phenomenon is still pending, so we made an attempt to fill this gap in the previous parts of our study by elaborating formulas for calculation of parasitic torques. It was a general demand among those who work in this field towards the author to verify his formulas with measurements. In the literature, it seems,only one detailed, purposeful series of measurements has been published so far, the purpose of which was to investigate the effect of the number of rotor slots on the torque-speed characteristic curve of the machine. The main goal of this study is to verify the correctness of the formulas by comparing them with the referred series of measurements. Relying on this, the expected synchronous parasitic torques were developed for the frequently used rotor slot numbers-as a design guide for the ***, together with our complete table for radial magnetic pull published in our previous work, the designer has all the principles, data and formulas available for the right number of rotor slots for his given machine and for the drive system. This brings this series of papers to an end.

关键词： Asynchronous parasitic torques Induction motor Squirrel cage rotor Space harmonics Synchronous parasitic torques

运动疲劳对男性前弓步动作时下肢的生物力学影响

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运动疲劳对男性前弓步动作时下肢的生物力学影响

Nonstationary laser-supported ionization wave in layer of porous substance with subcritical density

第十三届全国体育科学大会

作者：高立栋叶靖怡 kovács bálint Zsolt Radak Zhuqing Mao 顾耀东

研究目的:弓步是下肢肌肉力量训练和康复计划的一个重要部分。这项训练通常是为了加强下肢肌肉产生更高的力量的能力,特别是股四头肌,并尽量减少关节损伤的风险,以及发展功能性姿势平衡。与更常用的深蹲相比,弓步具有更多的平衡,因此它... 详细信息

研究目的:弓步是下肢肌肉力量训练和康复计划的一个重要部分。这项训练通常是为了加强下肢肌肉产生更高的力量的能力,特别是股四头肌,并尽量减少关节损伤的风险,以及发展功能性姿势平衡。与更常用的深蹲相比,弓步具有更多的平衡,因此它可以更安全地用于加强股四头肌和腘绳肌,这对于步态和日常生活活动的适当康复是必要的。在比赛和训练时涉及到弓步的运动可能贯穿整个运动过程。而肌肉疲劳的特点是长时间暴露在活动中后肌肉效率和产力能力下降,已多次被证明对运动表现有负面影响。疲劳是运动中一个主要的伤害危险因素,但疲劳前后弓步变化的研究却较为稀少。目前缺乏关注疲劳是如何诱发前弓步中运动学和动力学的变化的研究。尽管在不同方向上的弓步和疲劳后的下肢闭合链练习的运动学表现相关研究较为丰富,但缺乏关于疲劳前后相关肌肉群在弓步中的运动学、动力学和力量产生的变化的信息。本研究的目的是研究在完成疲劳方案之前和之后,疲劳对前弓步期间下肢生物力学的影响。疲劳是造成损伤风险的一个主要因素,通过我们的客观数据来理解疲劳具体影响到下肢的哪些方面,并根据以往的研究了解疲劳带来的损伤机制和预防相应的损伤,了解损伤的原因并提供所需的认识,并有助于改善损伤预防方案。研究方法:15名健康年轻男性参与本实验,在进行疲劳协议之前和之后,我们测试了向前弓步,以获得疲劳期间的运动学和动力学变化,并观察髋关节、膝关节和踝关节以及相应肌肉的力量变化。使用borg Scale RPE 6-20量表,该量表与心率检测器一起使用以记录在疲劳方案过程中的主观疲劳和心率(HR)变化。一组疲劳协议包括在固定跑步机上以自选速度进行跑步400m和20次重复向前弓步(优势腿与非优势腿交替向前弓步然后回到起始位置),此疲劳方案皆在模仿在运动或娱乐环境中可能经历的下肢运动模式。一组疲劳协议完成后若未疲劳则进入下一组协议,如此重复进行。疲劳是通过HR和RPE的值来确定的。除参与者自身无法继续进行外,还包括参与者的心率超过为其年龄计算的最大心率的90%和borg量表评分超过RPE> 17(非常困难)。使用八相机Vicon运动捕捉系统来捕捉运动轨迹。嵌入式Kistler三维测力板用于同步记录地面反作用力。本实验运用的该模型是基于原始OpenSim模型进行了调整,并更新了膝关节冠状面和水平面的额外运动范围。使用OpenSim软件来进行IK(逆运动学)、ID(逆动力学)和SO(静态优化)的处理。通过Delsys EMG测试系统同步采集股直肌、股二头肌长肌、胫骨前肌、腓肠肌的EMG信号与OpenSim静态优化算法输出的肌肉激活程度进行比较,对该模型进行了验证。在这之前使用CON-TRE-MJ等速肌力测试系统采集它们的最大自主收缩。本研究采用SPSS 26用来分析髋、膝和踝关节在矢状面和髋关节和膝关节在水平面的ROM,峰值角度,峰值力矩和疲劳前后下的峰值vGRF和两个峰值A和b,分别用配对样本T检验来分析是否具有显著性。分析前对数据先进行了Shapiro-Wilk正态性检验。研究结果:疲劳协议后,在髋关节的矢状面和水平面中,两者的峰值角度和关节活动范围(ROM)都有所增加,同时矢状面峰值力矩显著增大,躯干和骨盆运动幅度增大。膝关节矢状面的峰值角度和ROM也有所增加,同时在水平面上均有变化,然而在矢状面力矩减小,水平面有所增加。对踝关节来说,虽然ROM并没有明显变化,但峰值角度却明显降低,力矩显著下降。踝关节有更多的跖屈趋势。对于疲劳前后的vGRF,仅在初始接触峰值(A)减小。平均峰值和蹬离期峰值(b)并没有统计学意义,但平均峰值却略有增加而蹬离期峰值在减小,疲劳后踝关节的更多跖屈使得相应的反作用力减小。疲劳前后,股二头肌与腓肠肌的平均肌力和最大肌力均减小。股四头肌与胫骨前肌的平均肌力和最大肌力均增大。在这些肌肉中,股四头肌的平均肌力和最大肌力增加的最明显。研究结论:我们认为前弓步易受到疲劳的影响。即在疲劳后,髋关节和膝关节在矢状面有向前倾斜的趋势,以及在水平面的偏移增加,此外,踝关节的跖屈肌肉活动量增加,身体姿势表现不稳定,这表明膝关节、脚和踝关节可能有潜在的受伤风险。此外,股四头肌在疲劳后受到的影响最大。为了避免疲劳后不稳定造成的伤害,训练者应更注重髋关节和膝关节肌肉的力量训练和协调训练,以更有意识地控制躯干的稳定性。

关键词：前弓步运动学动力学疲劳

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Matter and Radiation at Extremes 2024年第1期9卷 58-70页

作者： S.Yu Gus’kov R.A.Yakhin P.N.Lebedev Physical Institute of Russian Academy of Sciences Leninskii Prospect 53Moscow 119991Russia

A time-dependent analytical solution is found for the velocity of a plane ionization wave generated under nanosecond laser pulse action on the surface of a flat layer of low-Z porous substance with density less than the critical density of the produced *** corrections for the two-dimensional nature of the problem when a laser beam of finite radius interacts with a flat target,this solution is in quantitative agreement with measurements of ionization wave velocity in various *** solution compared with experimental data covering wide ranges of performance conditions,namely,(3-8)×10^(14)W cm^(−2)for laser pulse intensity,0.3-3 ns for pulse duration,0.35-0.53μm for laser wavelength,100-1000μm for laser beam radius,380-950μm for layer thickness,4.5-12 mg cm^(−3)for average density of porous substance,and 1-25μm for average pore *** parameters of the laser beam that ensure the generation of a plane ionization wave in a layer of subcritical porous matter are determined for the problem statements and are found to meet the requirements of practical applications.

关键词： laser pulse porous

How to explore a new environment:exploratory tactics of the black rat(Rattus rattus)

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Current Zoology 2024年第3期70卷 371-382页

作者： Iveta Štolhoferová Veronika Rudolfová Hana Skalíková barbora Vobrubová Daniel Frynta Department of Zoology Faculty of ScienceCharles UniversityViničná712843 Prague 2Czechia

The black rat(Rattus rattus)is a unique model for studying exploratory tactics due to its enormous colonizing *** behavioral variability and consistent interindividual differences might help populations inhabit new environments and persist there even under intense ***,the affnity of the black rat for climbing might be another advantage,widening their potential *** this study,we describe the exploratory tactics of the black rats when introduced to a novel *** the frst experiment,we tested 12 rats and calculated repeatability of their behaviors across 12 sessions of an enriched open-feld *** concluded that climbing is a highly repeatable behavior that serves as an important source of interindividual *** the second experiment,we tested 24 black rats in a unique L-shaped *** rat was tested *** found that the majority of rats distributed their activity evenly,exploring each part of the apparatus for a similar amount of time,thus maximizing their chances of fnding ***,these“even”explorers still greatly differed in their level of activity,orderliness and affnity for climbing,generating large *** contrast,the minority of rats concentrated their activity only on a section of the new environment and were therefore characterized as selective ***,we concluded that a combination of such exploratory tactics as well as a bias for even explorers enables black rats to quickly colonize new environments and persist there even under unfavorable conditions.

关键词： 3D behavior climbing repeatability strategy.

Development of an ultrathin liquid sheet target for laser ion acceleration at high repetition rates in the kilohertz range

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High Power Laser Science and Engineering 2024年第3期 139-150页

作者： M.Füle A.P.kovács T.Gilinger M.Karnok P.Gaál S.Figul G.Marowsky K.Osvay National Laser-Initiated Transmutation Laboratory University of Szeged Department of Experimental Physics University of Szeged ELI ALPS ELI-HU Non-Profit Ltd. Department of Optics and Quantum Electronics University of Szeged Advanced Microfluidic Systems GmbH

A colliding microjet liquid sheet target system was developed and tested for pairs of round nozzles of 10, 11 and 18 μm in diameter. The sheet's position stability was found to be better than a few micrometers. Upon interaction with 50 mJ laser pulses, the 18 μm jet has a resonance amplitude of 16 μm at a repetition rate of 33 Hz, while towards 100 Hz it converges to 10 μm for all nozzles. A white-light interferometric system was developed to measure the liquid sheet thickness in the target chamber both in air and in vacuum, with a measurement range of 182 nm±1 μm and an accuracy of±3%. The overall shape and 3D shape of the sheet follow the Hasson±Peck model in air. In vacuum versus air, the sheet gradually loses 10% of its thickness, so the thinnest sheet achieved was below 200 nm at a vacuum level of 10±4mbar,and remained stable for several hours of operation.

关键词：

Introducing the Hong Kong Medical Journal and its important role in the timely dissemination of COVID-19 related knowledge

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Chinese Medical Journal 2024年第3期137卷 253-254页

作者： Rashid N Lui Kenneth KW Li Martin cs Wong Hong Kong Medical Journal Hong Kong SARChina The JC School of Public Health and Primary Care Faculty of MedicineThe Chinese University of Hong KongHong Kong SARChina

Hong Kong Medical Journal(HKMJ)is the flagship general medical journal in the Hong Kong Special Administrative Region,China,with an international *** are committed to publishing and promoting high-quality *** by our Editor-in-Chief,Professor Martin cs Wong,our Editorial board is pleased to collaborate with *** Wang,the Editor-in-Chief of the Chinese Medical Journal(CMJ),as well as the editors of CMJ to enhance the visibility of our respective journals and foster a collaborate environment that brings forth ideas and knowledge to our readers.

关键词： journal knowledge visibility

Enabling Technologies for Autonomous Robotic Systems in Manufacturing

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Transactions of Nanjing University of Aeronautics and Astronautics 2024年第4期41卷 403-431页

作者： ERDŐS Gábor AbAI Kristóf bEREGI Richárd csEMPESZ János csERTEG Tamás GODÓGábor HAJÓS Mátyás HÁY borbála HORVÁTH Dániel HORVÁTH Gergely JUNIKIÁdám KEMÉNY Zsolt kovÁcs András NAcsA János PANITI Imre PEDONE Gianfranco TAKÁcs Emma TIPARY bence ZAHORÁN László VÁNCZA József Institute for Computer Science and Control Hungarian Research Network(HUN-REN SZTAKI)BudapestHungary Department of Manufacturing Science and Technology Budapest University of Technology and Economics(BME)BudapestHungary EPIC InnoLabs Nonprofit Ltd. BudapestHungary Eötvös Loránd University(ELTE) BudapestHungary

Research of autonomous manufacturing systems is motivated both by the new technical possibilities of cyber-physical systems and by the practical needs of the *** operation in semi-structured industrial environments can now be supported by advanced sensor technologies,digital twins,artificial intelligence and novel communication *** enable real-time monitoring of production processes,situation recognition and prediction,automated and adaptive(re)planning,teamwork and performance improvement by *** paper summarizes the main requirements towards autonomous industrial robotics and suggests a generic workflow for realizing such *** case studies will be presented from recent practice at HUN-REN SZTAKI in a broad range of domains such as assembly,welding,grinding,picking and placing,and *** various solutions have in common that they use a generic digital twin concept as their *** making general recommendations for realizing autonomous robotic solutions in the industry,open issues for future research will be discussed.

关键词： industrial robotics autonomy digital twin enabling technology

Transient transport processes in deformable porous media

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Chinese Physics b 2011年第11期20卷 167-175页

作者： cs.Mészáros A.bálint Szent István University Department of Physics and Process Control Szent István University Department of Chemistry and Biochemistry

The basic partial differential equations relevant for convection-diffusion and convection-diffusion-wave phenomena arc presented and solved analytically by using the MAPLE symbolic computer algebra system. The possible general nonlinear character of the constitutive equation of the convection-discussion process is replaced by a direct posteriori stochastic refinement of its solution represented for Dirichlet-type boundary conditions. A thermodynamic analysis is performed for connecting the relaxation time constants and Jacobi-determinants of deformations at transient transport processes. Finally, a new procedure for general description of coupled transport processes on the basis of the formalism originally developed for convection-free phenomena is presented by matrix analysis methods in the Fourier space.

关键词： convection binary mixtures relaxation time matrix polynomials

Long-term outcomes after endoscopic removal of malignant colorectal polyps:Results from a 10-year cohort

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World Journal of Gastrointestinal Endoscopy 2024年第4期16卷 193-205页

作者： Anna Fábián Renáta bor béla Vasas Mónika Szűcs Tibor Tóth Zsófia bősze Kata Judit Szántó Péter bacsur Anita bálint bernadett Farkas Klaudia Farkas Ágnes Milassin Mariann Rutka Tamás Resál Tamás Molnár Zoltán Szepes Department of Internal Medicine University of SzegedSzent-Györgyi Albert Medical SchoolSzeged 6725Hungary Department of Pathology University of SzegedSzent-Györgyi Albert Medical SchoolSzeged 6725Hungary Department of Medical Physics and Medical Informatics University of SzegedSzent-Györgyi Albert Medical SchoolSzeged 6720Hungary USZ Translational Colorectal Research Group Hungarian Centre of Excellence for Molecular MedicineSzeged 6725Hungary

bACKGROUND Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging,and evidence regarding a surveillance-only strategy is *** To evaluate long-term outcomes after endoscopic removal of malignant colorectal *** A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and *** disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were *** rates for categorical variables and means for continuous variables with 95%confidence intervals were calculated,and Fisher’s exact test and Mann-Whitney test were *** risk factors of adverse outcomes were RESULTS In total,135 lesions(mean size:22.1 mm;location:42%rectal)from 129 patients(mean age:67.7 years;56%male)were *** proportion of pedunculated and non-pedunculated lesions was similar,with en bloc resection in 82%and 47%of lesions,*** differentiation,distance from resection margins,depth of submucosal invasion,lymphovascular invasion,and budding were reported at 89.6%,45.2%,58.5%,31.9%,and 25.2%,*** tumor was found in 10 patients,and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical *** analysis identified piecemeal resection as a risk factor for residual malignancy(odds ratio:1.74;P=0.042).At least 1 year of follow-up was available for 117 lesions from 111 patients(mean follow-up period:5.59 years).Overall,54%,30%,30%,11%,and 16%of patients presented at the 1-year,3-year,5-year,7-year,and 9-10-year surveillance *** outcomes occurred in 9.0%(local recurrence and dissemination in 4 patients and 9 patients,respectively),with no difference between patients undergoing secondary surgery and surveillance *** Reporting of histological featur

关键词： Malignant colorectal polyps T1 tumor Endoscopic removal Outcomes Long-term Surveillance

Weak influence of natural vegetation in urban green spaces compared to agricultural ecosystems on House Martin populations:Insights from nationwide citizen science data in the Czech Republic

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Avian Research 2024年第2期15卷 139-146页

作者： Denisa Dvorakova Jan Sipos Josef Suchomel Department of Zoology FisheriesHydrobiology and ApicultureMendel University in BrnoZemedelska 161300BrnoCzech Republic

The House Martin(Delichon urbicum)is a common farmland bird species in the European landscape,yet its population numbers are currently in ***,it is not yet sufficiently explained why this long-term decline *** fill this gap in our knowledge,we investigated how land cover composition affects the abundance of House Martins on the landscape scale by using nationwide citizen science *** a generalised linear mixed-effect model(GLMM),we evaluated 12,094 records from the Czech Republic spanning *** analysis underscores the significance of land cover type in shaping House Martin *** specifically,our results indicate that within agricultural land covers“naturally managed arable lands”exhibited significant positive effect,while forests,orchards,and vineyards were deemed less favourable for House Martin *** urban land covers,we found a clear distinction in the impact on House Martin populations,with a positive effect observed in urban infrastructure,development areas,and post-industrial sites(i.e.,UrbanAreas),while an indifferent impact was noted within urban green spaces and landscaped areas(i.e.,GreenUrban).Notably,our findings suggest that the simple spatial,age,and species structure typical of forests in Europe,and similarly,the uniform structure of parks and gardens,may be responsible for the decline in the abundance of the House *** advocate for the preservation or enhancement of urban greenery,expansion of natural vegetation in rural areas and adoption of ecological management practices in orchards and vineyards to mitigate further declines in House Martin populations.

关键词： Citizen science Habitat preferences House Martin Species distribution Urban and suburban landscape